Bug 1796582 - [devtools] Use distinctSystemPrincipalLoader instead of invisibleToDebugger when possible r=ochameau

Differential Revision: https://phabricator.services.mozilla.com/D160214

devtools/client/framework/browser-toolbox/window.js

@@ -4,7 +4,12 @@
 
 "use strict";
 
-var { loader, require, DevToolsLoader } = ChromeUtils.importESModule(
+var {
+  loader,
+  require,
+  useDistinctSystemPrincipalLoader,
+  releaseDistinctSystemPrincipalLoader,
+} = ChromeUtils.importESModule(
   "resource://devtools/shared/loader/Loader.sys.mjs"
 );
 
@@ -260,15 +265,16 @@ async function openToolbox(commands) {
   }
 }
 
+let releaseTestLoader = null;
 function installTestingServer() {
   // Install a DevToolsServer in this process and inform the server of its
   // location. Tests operating on the browser toolbox run in the server
   // (the firefox parent process) and can connect to this new server using
   // initBrowserToolboxTask(), allowing them to evaluate scripts here.
 
-  const testLoader = new DevToolsLoader({
-    invisibleToDebugger: true,
-  });
+  const requester = {};
+  const testLoader = useDistinctSystemPrincipalLoader(requester);
+  releaseTestLoader = () => releaseDistinctSystemPrincipalLoader(requester);
   const { DevToolsServer } = testLoader.require(
     "resource://devtools/server/devtools-server.js"
   );
@@ -319,6 +325,10 @@ function updateBadgeText(paused) {
 function onUnload() {
   window.removeEventListener("unload", onUnload);
   gToolbox.destroy();
+  if (releaseTestLoader) {
+    releaseTestLoader();
+    releaseTestLoader = null;
+  }
 }
 
 function quitApp() {

devtools/client/framework/test/allocations/head.js

@@ -10,14 +10,18 @@
 //
 // If we want to track DevTools module loader we should ensure loading Loader.sys.mjs within
 // the `testScript` Function. i.e. after having calling startRecordingAllocations.
-let tracker;
+let tracker, releaseTrackerLoader;
 {
-  const { DevToolsLoader } = ChromeUtils.importESModule(
+  const {
+    useDistinctSystemPrincipalLoader,
+    releaseDistinctSystemPrincipalLoader,
+  } = ChromeUtils.importESModule(
     "resource://devtools/shared/loader/Loader.sys.mjs"
   );
-  const loader = new DevToolsLoader({
-    invisibleToDebugger: true,
-  });
+
+  const requester = {};
+  const loader = useDistinctSystemPrincipalLoader(requester);
+  releaseTrackerLoader = () => releaseDistinctSystemPrincipalLoader(requester);
   const { allocationTracker } = loader.require(
     "chrome://mochitests/content/browser/devtools/shared/test-helpers/allocation-tracker.js"
   );
@@ -86,12 +90,16 @@ async function startRecordingAllocations({
       gBrowser.selectedBrowser,
       [DEBUG_ALLOCATIONS],
       async debug_allocations => {
-        const { DevToolsLoader } = ChromeUtils.importESModule(
+        const {
+          DevToolsLoader,
+          useDistinctSystemPrincipalLoader,
+          releaseDistinctSystemPrincipalLoader,
+        } = ChromeUtils.importESModule(
           "resource://devtools/shared/loader/Loader.sys.mjs"
         );
-        const loader = new DevToolsLoader({
-          invisibleToDebugger: true,
-        });
+
+        const requester = {};
+        const loader = useDistinctSystemPrincipalLoader(requester);
         const { allocationTracker } = loader.require(
           "chrome://mochitests/content/browser/devtools/shared/test-helpers/allocation-tracker.js"
         );
@@ -99,9 +107,11 @@ async function startRecordingAllocations({
         // because we may easily leak web page objects, which aren't in DevTools global.
         const tracker = allocationTracker({ watchAllGlobals: true });
 
-        // /!\ HACK: save tracker and doGC on DevToolsLoader in order to be able to reuse
-        // them in a following call to SpecialPowers.spawn
+        // /!\ HACK: store tracker and releaseTrackerLoader on DevToolsLoader in order
+        // to be able to reuse them in a following call to SpecialPowers.spawn
         DevToolsLoader.tracker = tracker;
+        DevToolsLoader.releaseTrackerLoader = () =>
+          releaseDistinctSystemPrincipalLoader(requester);
 
         await tracker.startRecordingAllocations(debug_allocations);
       }
@@ -232,7 +242,19 @@ async function stopRecordingAllocations(
         },
       ],
     });
+
+    // Finally release the tracker loader in content process.
+    await SpecialPowers.spawn(gBrowser.selectedBrowser, [], () => {
+      const { DevToolsLoader } = ChromeUtils.importESModule(
+        "resource://devtools/shared/loader/Loader.sys.mjs"
+      );
+      DevToolsLoader.releaseTrackerLoader();
+    });
   }
+
+  // And release the tracker loader in the parent process
+  releaseTrackerLoader();
+
   // Log it to stdout so that perfherder can collect this data.
   // This only works if we called `SimpleTest.requestCompleteLog()`!
   info("PERFHERDER_DATA: " + JSON.stringify(PERFHERDER_DATA));

devtools/client/shared/test/shared-head.js

@@ -31,12 +31,17 @@ if (DEBUG_ALLOCATIONS) {
   // Use a custom loader with `invisibleToDebugger` flag for the allocation tracker
   // as it instantiates custom Debugger API instances and has to be running in a distinct
   // compartments from DevTools and system scopes (JSMs, XPCOM,...)
-  const { DevToolsLoader } = ChromeUtils.importESModule(
+  const {
+    useDistinctSystemPrincipalLoader,
+    releaseDistinctSystemPrincipalLoader,
+  } = ChromeUtils.importESModule(
     "resource://devtools/shared/loader/Loader.sys.mjs"
   );
-  const loader = new DevToolsLoader({
-    invisibleToDebugger: true,
-  });
+  const requester = {};
+  const loader = useDistinctSystemPrincipalLoader(requester);
+  registerCleanupFunction(() =>
+    releaseDistinctSystemPrincipalLoader(requester)
+  );
 
   const { allocationTracker } = loader.require(
     "resource://devtools/shared/test-helpers/allocation-tracker.js"